The number of Americans initially applying for unemployment aid last week fell dramatically, a sign for a strong recovery in the labor market, the U.S. Labor Department reported Thursday.

The Labor Department said that the advance figure for seasonally adjusted initial claims for jobless benefits was 352,000 in the week ending Jan. 14, a decrease of 50,000 from the previous week's revised figure. It was the biggest drop in more than six years.

The fresh figure came after three months of steady declines that brought applications to their lowest level in nearly four years, signaling that the hiring market is strengthening.

As a rule of thumb, fewer than 425,000 people applying for aid is consistent with modest job growth, and 375,000 or below signals a sustained drop in the unemployment rate.

Meanwhile, the four-week moving average, which helps to smooth out week-to-week volatility, edged down by 3500 to 379,000, the second-lowest in more than three years.

The advance figure for seasonally adjusted insured unemployment during the week ending Jan. 7 was 3.43 million, a decrease of 215,000 from one week earlier.

A department spokesman cautioned that volatility at this time of year is common. Applications had jumped two weeks ago, largely because companies laid off thousands of temporary workers hired for the holidays.

The weekly figures of jobless benefits application reflect the level of layoffs and indicate real-time condition of the American job market.